What is the URL rewriting?
The URL rewriting is a method that makes possible to present more understandable URLs to internauts by enabling to hide the name of parameters whose usefulness is just technical.
It is then easier to offer URLs that are simpler to understand for users by inserting appropriate keywords, among other possibilities.
Here is an example without URL rewriting:
http://www.domain.com/article.php?id=3
And now the result with URL rewriting:
http://www.domain.com/3-example-seo
Technically, today, search engines are fully capable of indexing non-rewritten URLs containing many parameters.
The advantages for the Internet users are obvious. From a results page,an understandable URL is an undeniable advantage.
URLs containing interesting keywords may be slightly advantaged by search engines. It is a criteria among many others.
To finish with, the URL rewriting - without being mandatory - is now getting close to becoming one of the unavoidable optimizations considering how easy it is to set it up.
But above all, this optimization will, to date, be more beneficial to the internaut than to the search engine.
Nevertheless, it is not to be neglected in terms of "Call To Action".